1. Field of the Invention
The invention relates generally to digital scan converters and, in particular, to a digital scan converter with a randomized decay function simulating the exponential decay of a selected cathode ray tube phosphor.
2. Description of the Prior Art
U.S. Pat. No. 4,165,506 discloses a control unit for the brightness of video on a raster scan display provided with a random-access memory (RAM). The data stored in each element of the RAM determines the brightness of the video signals on the raster scan display at a position corresponding with the element. In response to the video data supplied to the control unit and the brightness data in the RAM, a logic unit provides new brightness data which overwrites the brightness data stored in the RAM. This technique requires the use of extra memory cycles to achieve the desired change in brightness levels. In addition, an address and video data generator must address the RAM and modify the brightness data.